Vehicle theft is a well known problem that is perpetrated by amateur and professional criminals and vandals. To a thief, one of the most profitable methods of disposing with a stolen vehicle is to sell the engine components since these can often fetch more money collectively than the vehicle in one piece. Also, splitting the vehicle into components makes solving the crime more difficult for law enforcement authorities. Of course many thieves are after the vehicle itself, and others are after the contents of the storage compartment.
A multitude of alarm and deterrent systems to guard against vehicle theft have been introduced.
U.S. Pat. No. 5,193,141 to Zwern discloses a vehicle mounted system which permits a user to record desired phrases and to play back the recorded phrases through an audio system for entertainment, requesting assistance, or announcing conditions of the vehicle, including whether the vehicle has been disturbed.
U.S. Pat. No. 5,148,145 to Tsao discloses an automobile alarm device which, in response to the detection of a theft, alternately activates (i) a siren and (ii) a speech sound signal corresponding to the vehicle's license plate. The purpose of this device is to provide a distinct alarm signal so that the driver would know that the sound was coming from his vehicle.
U.S. Pat. No. 1,284,328 to Haynes et al. discloses a theft alarm system including a box mounted to the front of a car and another box mounted to the rear of the car. The front box has a lower portion with an audible alarm and an upper portion can indicate a visual "stolen" signal by illuminating a light behind a perforated plate. The rear box is similar to the upper portion of the front box and creates a visual "stolen" sign.
U.S. Pat. No. 4,901,054 to Waterman, U.S. Pat. Nos. 4,897,630 and 5,117,217 to Nykerk and U.S. Pat. No. 5,451,926 to Li all disclose vehicle alarm systems which include a voice synthesizer and/or voice generation circuits to inform the owner or occupant not to take further action in an attempt to deter theft and vandalism. Nykerk ('630 and '217) and Li include a transmitter or a dialer to contact the owner and/or third party.
U.S. Pat. No. 5,534,845 to Issa et al. discloses a complex vehicle security system having multiple audio, visual, and electronic output devices. The output devices can include sirens, synthesized and voiced outputs, the vehicle's head-, running and dome lights, dash mounted LEDs, and horn.
U.S. Pat. No. 2,041,325 to De Lannoy discloses an automobile distress signal. Upon activation by a driver stepping on a pedal the license plate pivots downwardly to disclose a "Help Police" sign and a card with a listing of various vehicle and owner information.
U.S. Pat. No. 5,463,595 to Rodhall et al. discloses a portable security device including a motion detector, illumination devices, audible devices, and a telephone dialer which all activate in response to an intruder. One audible device can play a message prerecorded by the user
U.S. Pat. No. 4,958,142 to Sayers discloses a motor vehicle theft deterrent system which includes a high pitched siren and nozzles that spray an irritant onto the would-be thief.
U.S. Pat. No. 2,763,745 to Watts discloses a theft alarm system for vehicles which operates independently from the ignition system to send an alarm upon the opening of a front door of the vehicle.
While the prior alarm and deterrent systems provide audio and visual warnings, the warnings do not deter a thief from easily accessing the engine or trunk compartments.